Massive memory usage

Hi to everybody.
I'm running 2 mailservers with ISPConfig 3.0.1.6, master-master replicated (master-master replication of mysql and /var/vmail with glusterfs).
Yesterday one of the server crashed, without giving me even the possibility to enter in ssh. Luckly my server farm gave me the opportunity to enter with serial, and I saw some segmentation fault for clamd, but I was able to see just that error, because the server was not responding to commands.
I'm checking the memory to see if it was an hardware fault.
The other server is up and running. It is less powerfull that the other one (just 1 gb of ram). I can see that I've a massive usage of memory... and I'm just scare that probably the other server crashed for the same reason...
From the server that is now running, I've this usage of memory:

As you can see, clamd is taking 17% of memory, even without usage of CPU.
also Amavis is using quite a lot of memory. Is it normal that amavis is using 3 daemons?
I saw before that the free memory is jumping from 10MB to 300MB...

Well, the traffic is increased a lot because before all the traffic was shared between the 2 servers... yesterday one of the servers went down and now all the emails are managed from just one server.
Anyway still sound strange to me that clamd is reserving all this memory...

So why it's in the how-to if at the end ispconfig is not using it?
Can I even remove it?

Click to expand...

If you would remove it then you would remove amavisd with it and if it would not be needed then it would not have been part of the perfect setup tutorial. So what I told you above is to stop it and not to remove it.

If you would remove it then you would remove amavisd with it and if it would not be needed then it would not have been part of the perfect setup tutorial. So what I told you above is to stop it and not to remove it.

Click to expand...

So Till you mean just kill the PID related with spamd?
Any idea why the free memory is jumping too much?
Could it be the cause of the crash of yesterday in one of the server? (they was online working perfectly for like 8 months)

Hello,
unfortunately also without the spamd process, the usage of memory is jumping, in both servers, really a lot.
For example srv1 (4GB ram) is jumping from 1.8GB free to 30MB free... srv2 (1GB ram) is jumping from 500MB free to 20MB free...

Anyway I still don't know how was possible the crash of srv1 2 days ago... it was something related with the segmentation fault... I've run a test of the RAM, but it was fine, so it was not an hardware fault...